CStrings

// System.Runtime.InteropServices.CStrings — System.Core (decompiled from Larva HIR)

import System;

into namespace System.Runtime.InteropServices
{
	/// Temporary C strings: what the compiler calls around an imported function that takes strings.
	static class CStrings
	{
		public:
			unsafe extern("mem.alloc") Allocate(i64 bytes) : u8*;

			unsafe extern("mem.free") Release(u8* block);

			/// A null-terminated UTF-8 copy of `text` (Free gives it back).
			unsafe Utf8(str text) : u8*
			{
				u8[] units = text.Units();
				i32 n = units.Length;
				u8* copy = Allocate((i64)n + 1);
				loop (i32 i = 0..n)
					*(copy + (i64)i) = units[i];
				return copy;
			}

			/// A null-terminated UTF-16 copy of `text` (Free16 gives it back).
			unsafe Utf16(String<u16> text) : u16*
			{
				u16[] units = text.Units();
				i32 n = units.Length;
				u16* copy = (u16*)Allocate(2 * ((i64)n + 1));
				loop (i32 i = 0..n)
					*(copy + (i64)i) = units[i];
				return copy;
			}

			/// `text` null-terminated into `buffer` (`capacity` units) when it fits: whether it did.
			unsafe Utf8Into(str text, u8* buffer, i32 capacity) : bool
			{
				u8[] units = text.Units();
				i32 n = units.Length;
				if (n >= capacity)
					return false;
				loop (i32 i = 0..n)
					*(buffer + (i64)i) = units[i];
				*(buffer + (i64)n) = 0;
				return true;
			}

			unsafe Utf16Into(String<u16> text, u16* buffer, i32 capacity) : bool
			{
				u16[] units = text.Units();
				i32 n = units.Length;
				if (n >= capacity)
					return false;
				loop (i32 i = 0..n)
					*(buffer + (i64)i) = units[i];
				*(buffer + (i64)n) = 0;
				return true;
			}

			unsafe Free(u8* block)
			{
				Release(block);
			}

			unsafe Free16(u16* block)
			{
				Release((u8*)block);
			}

			/// How many units come before the first 0.
			unsafe Length8(u8* text) : i32
			{
				i32 n = 0;
				loop (*(text + (i64)n) != 0)
					n++;
				return n;
			}

			unsafe Length16(u16* text) : i32
			{
				i32 n = 0;
				loop (*(text + (i64)n) != 0)
					n++;
				return n;
			}
	}
}